Fin damping means



H. FRANCISCO, JR

Aug. l5, 1950 FIN DAMPING MEANS Filed March ll, 1947 for damping vibration of said fins.

Athe invention comprises drilling an axially alined Patented Aug. 15, 1950 UNITED STATES PATENT oFFIcEj- FIN DAMPING MEANS William H. Francisco, Jr., Bloomfield, N. J., as-

signor to Wright Aeronautical Corporation, a corporation of New York Application March 11, 1947, Serial No. 733,859

7 Claims. l

This invention relates to vibration damping means and is more particularly directed to means for damping vibrations of ns projecting from a body which is to be heated or cooled as a result of the ow of a heat exchange uid through the passages between the fins.

The cylinders of air cooled internal combustion engines are provided with a plurality of spaced iins projecting therefrom and between which relatively cool air is caused to flow for cooling the engine. One of the problems encountered with such cooling n structures is that engine vibrations may induce destructive resonant vibration of the fins. An object of this invention is to provide a simple and novel means Specically,

series of holes through the iins and inserting an elongate member of rubber-like material through said holes so that said material is squeezed out into the spaces between the ns.

Other objects of the invention will become apparent upon reading the annexed detailed description in connection with the drawing in which:

Figure 1 is a sectional View through a body having a plurality of heat exchange ns projecting therefrom and having a series of axially alined holes therethru;

Figure 2 is a sectional View taken along line 2 2 of Figure l with vibration damping means of the present invention installed in position on the fins;

Figure 3 is a side elevational view of the damping means illustrated in Figure 2, prior to its installation on the uns;

Figure 4 is a vier.7 similar to Figure 2 but illustrating a modified form of vibration damping means; and

Figure 5 is aview similar to Figure 2 but illustrating a further modified form of vibration damping means.

Referring rst to Figures 1 to 3, a body I0, which may comprise a portion of the cylinder head of an internal combustion engine, is provided with a plurality of substantially parallel heat exchange ns I2 projecting therefrom and between which a heat exchange fluid is adapted to flow. In order to dampen vibration of the fins I2, they are provided with a series of axially alined holes I4 extending therethrough inwardly of the outer edges of the ns--for example, by drilling through the plurality of fins as a unit structure. An elongate member I5 of rubberlike material extends through said axially alined holes I4 in such a manner that the rubber-like material of said member is squeezed out into the spaces between the fins I2. With this arrange-' ment, the engagement of the fins with the rubber-like member I6 and the portion of the material of this member projecting between the iins eiiectively dampens vibration of the iins relative to each other and, at the same time, the plurality of the iins are not rigidly secured together for vibration as a unit. The holes. IG may be drilled normal to the surface of the ns I2. However, with the holes drilled at an angle substantially inclined to the 1in surface, as illustrated, the member I6 is more effective to dampen fin vibration. For clarity a portion of Figure 2 has been magnified as indicated at I'I.

In order to install the damper member IE5, it is initially formed as a solid cylindricalrod of rubber-like material with a hook i8 molded into each end as illustrated. In its free conditionthat is, in the absence of external forcesthe member I6 has an outer diameter substantially largerV than the internal diameter of said holes III. The hooks I3 provide means whereby the member I6 may be strained vby stretching to reduce itsY external diameter in order to permit insertion of this member through the alined holes I4. Thus, a suitable wire-like member may be passed through the alined holes Il -and attached to one of the hooks I8 whereby the damp-er member I5 may be stretched until its external diameter is reduced sufliciently to permit it to be inserted through the holes I4. After the damper member I6 has been inserted through the holes, the tension in the member I, applied at the hooks I8, is removed whereupon the member i8 tends to return to its original diameter and, in so doing, expands diametrcally into the spaces between the ns, The projection of the damper member I6Y laterally into the spaces between the fins not only dampens vibration of the fins but also effectively secures this member to the iins without the provision of special means for this purpose, The two projecting ends of the damper member I6 may be cut 01T flush with the outer surface of the ns as illustrated in Figure 2, in which ligure the cut-off portions of this member are illustrated by dot and dash lines.

Figure'l illustrates a modified form of a member for damping vibrations of the ns I 2. In

Figure 4, the damper member 30 is a tubular member of rubber-like material closed at one end 32. The damper member 3G has a free external diameter greater than the internal diameter of the holes I4 in the fins. A rod 314 is adapted to be inserted into the tubular member against its closed end 32 and the member Sii is stretched over the rod 34 until its external diameter has been reduced suiciently to permit it to be inserted through the alined holes I4 in the fins I2. After the damper member 3) has been inserted through said holes I4, the tension in said member is released by removing the rod S from the damper member 3D whereupon this member tends to expand back to its original diameter thereby expanding into the spaces between the ns I2. As illustrated inFigure 4, the projecting ends of the damper member 3Q' may be cut off flush with the ns.

Figure 5 illustrates a further modified form of the damper member. In this modification a damper member 4G is tubular and is made of rubber-like material but the external diameter of this member is such as to permit it to be inserted through the alined holes I4 in its free condition. After the member has been inserted through the holes I4, a relatively rigid rod 42, having an external diameter somewhat larger than the free internal diameter of the damper member 40, is forced therethrough, For this purpose, the one end of the rod 42 is tapered, as illustrated, at 44. Because the rod 42 has an external diameter larger than the free internal diameter of the rubber-like member 4S, the material of this member is forced into the spaces between the fins I2 when the rod 42 is forced through said member. The projecting ends of the rod 42 and member 40 may be cut oif flush with the end fins. In addition, some means-as a Cotter pin 46-may be provided to maintain the rod 42 in position within the tubular damper member 40.

In all of the aforedescribed modifications of the invention, an elongate damper member of rubber-like material extends through an axially alined series of holes in a plurality of fins with the rubber-like material of said member extending laterally into the spaces between the fins thereby providing an eifective arrangement for damping vibrations of the fins. In addition, the damping means is of simple construction, can readily be installed and the projection of the rubber-like material of said damping means into the spa-ces between the fins secures said damping means to said fins without the addition of special means for this purpose.

While I have described my invention in detail in its present preferred embodiments, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modications.

I claim as my invention: f'

1. In combination; a body having a plurality of heat exchange ns projecting therefrom, said fins having a series of axially alined holes therethrough; and means for suppressing vibration of said fins, said means comprising an elongate member of rubber-like material extending through said holes, said member having a circumferentially continuous outer surface which projects laterally into the annular spaces about said member between pairs of adjacent fins.

2. In combination; a body having a plurality of heat exchange fins projecting therefrom, said fins having a series of axially alined holes therethrough; and means for suppressing vibration of said fins, said means comprising a cylindrical member of rubber-like material extending through said holes and having a circumferentially continuous outer surface with a free external diameter greater than the diameter of said holes whereby the material of said member projects laterally therefrom into the spaces between said fins.

3. In combination; a body having a plurality of heat exchange i'lns projecting therefrom, said ns having a series of axially alined holes therethrough; and means for suppressing vibration of said ns, said means comprising a solid rod or rubber-like material extending through said holes and projecting laterally into the spaces between said fins.

4. In combination; a body having a plurality of heat exchange ns projecting therefrom, said having a series of axially alined holes therethrough; and means for suppressing vibration of said ns, said means comprising a tubular member having a circumferentially continuous annular wall about its hollow interior, said member being of rubber-like material and extendthrough Said holes and projecting laterally into the spaces between said fins.

5. In combination; a'body having a plurality of heat exchange ns projecting therefrom, said fins having a series of axially alined holes therethrough; and means Ifor suppressing vibration of said fins, said means comprising a tubular member of rubber-like material extending through said holes; and a relative rigid rod extending through said tubular member, said rod having an external diameter greater than the free internal diameter of said tubular member such that said rod forces the material of said member laterally into the spaces between said fins.

6. In combination; a body having a plurality of heat exchange fins projecting therefrom, said fins having a series of axially alined holes therethrough substantially inclined to the surface of said fins; and means for suppressing vibration of said fins, said means comprising an elongate member of rubber-like material extending through said holes, said member having a circumferentially continuous outer surface which projects laterally into the annular Spaces about said member between pairs of adjacent ns.

'7. In combination; a body having a plurality of heat exchange fins projecting therefrom, said fins having a series of alined holes therethrough; and. means for suppressing vibration of said fins, said means comprising a member of rubber-like material extending through said holes, said member having a circumferentially continuous cylindrical outer surface with a free diameter greater than the diameter of said holes prior to insertion into said holes so that said member must be strained to reduce its external diameter to permit its vinsertion into said holes and, upon insertion into said holes and upon removal of said strain, the material of said member projects laterally into the annular spaces about said member between pairs of adjacent fins.

TILLIAM H. FRANCISCG, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,253,625 Fedden et al Aug. 19, 1941 2,396,363 Du Bois et al Mar. l2, 1946 

